So I'm assuming most are familiar with the rattle at start up on IS250s. From what I've been told this is do to a lack of lubrication on the gears at startup. Would something like Lucas oil stabilizer in the crankcase work to stop the noise on startup?

 

Worth taking a shot at it. I noticed in the summer on the hottest of days that mine would "rattle" only when I parked on an incline at work. The "rattle" would only happen nearing the end of my oil change interval. Wish Lexus would just add the IS250 to the recall for this known issue.

 

When I first bought my car, I noticed the rattle a couple times, but after doing an oil change and using full synthetic, it went away. I eventually got the recall done as well and have not heard the noise since.

What oil are you using now?

 

Whatever the dealer uses

 

Had the rattle on my 350 but dealer fixed it with recall and now it's gone. Have always used Mobil 1 or PP synthetic oil since I owned it.

 

I had this problem 11 years ago. The tech at the dealer said use 0w oil. I opted for 0w30 amsoil and after 1000km the sound went away and never came back to date. I still have the car. I used pennzoil 0w30 2 times recently and no issues, so this isn't me promoting amsoil. I'm thinking about switching to high mileage oil or adding high mileage additives with the oil change, but I'm affraid the sound might come back. What do you guys think?